This invention relates to a laser beam pendular level.
Generally speaking, it is known that to perform sightings and tracings, devices combining a spirit level system with a laser beam emitter have been proposed.
For example, U.S. patent application Ser. No. 08/160,250 to Breda, outlines a device using:
a calibrated tube, inside which resides a solid state laser emitting component of which the optical emitting axis coincides with the mechanical axis of the tube; PA1 means of reflecting the laser beam in a given direction towards the said axis; PA1 means of rotating the tube around this axis; and PA1 a tube support equipped with spirit levels of which the axis define an orthonormal mark.
Because of its design, such a device requires, each time it is used, an accurate adjustment of the vertical orientation of the tube axis, using the levels placed on the structure.
Practically, this operation turns out to be delicate and tedious to perform and this, all the more so, since sighting distances are significant and therefore, adjustments must be very accurate.
Furthermore, the visibility of spirit levels is often poor because of their small size, their position, and the dust which partially obscures them.
In addition, this type of device is normally used on construction sites in conditions unfavourable to allow one to perform adjustments with an high accuracy level.